/*
 * Copyright 2002-2009 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.expression;

/**
 * 将表达式字符串解析为可计算的已编译表达式。支持分析模板（Template）和标准表达式字符串。
 * 它是一个抽象，并没有要求具体的语法规则，Spring实现的语法规则是：SpEL语法
 *
 * @author Keith Donald
 * @author Andy Clement
 * @since 3.0
 */
public interface ExpressionParser {

	// 他俩都是把字符串解析成一个Expression对象~~~~  备注expressionString都是可以被 repeated evaluation的
	Expression parseExpression(String expressionString) throws ParseException;

	Expression parseExpression(String expressionString, ParserContext context) throws ParseException;

}
